 
 (def tens ["twenty" "thirty" "forty" "fifty" "sixty" "seventy" "eighty" "ninety"])
 
-(defn to-words
+(defn to-words [n]
   "Converts a number (up to 1000) into its string representation, omitting spaces.
   Example: (to-words 115) => 'onehundredandfifteen'."
-  [n]
   (cond
     (< n 20) (nth singles (dec n))
     (< n 100) (if (factor? n 10)

     (factor? num (first ps)) (prime-factors (/ num (first ps)) (conj factors (first ps)) ps)
     :else (prime-factors num factors (rest ps)))))

(defn palindrome?
  "*Int -> Bool*
	Checks whether the given number n is a palindrome.
	Uses reversed string comparison"
  [n] (= (str n) (clojure.string/reverse (str n))))

(defn least-common-multiple
  "*[Int] -> Int*
	Computes the smallest number divisible by all of the given input numbers."
  [input]
  (->> input
       (map #(frequencies (get-primes %)))
       (apply merge-with max)

    (boolean (some #(factor? argument %) divisors))))

(defn divisors
  "**divisors :: Int -> [Int]**:
  The divisors of n (excluding n)"
  [n] (filter factor? (range 1 n)))

(defn factors
  "**factors :: Int -> [Int]**
  Returns all numbers that evenly divide n."
  ([n] (factors n 1))
  ([n start]
